Functionalization of silicon metal during a milling process renders the silicon highly sensitive to impurities, especially oxygen and moisture. The surface of fractured silicon includes reactive silicon radicals that can react with such impurities when present. Silicon oxygen bonds are thermodynamically favorable when compared to almost any other silicon bond, accordingly, silicon radicals quickly and efficiently react with any and all available oxygen atoms.
Unless housed in an inert atmosphere, milling equipment will have moisture and air trapped in the system, which can be introduced during cleaning operations or while open to the atmosphere during the loading of milling media. Excluding all sources of contamination during the handling of the milling equipment (vessel components) and/or starting materials (e.g., during loading) is an ongoing challenge. Existing methods of addressing the above presently involves the use of dry rooms and glove boxes, which have limitations related to cost, lack of throughput, and effectiveness.
The present disclosure provides systems and methods to remove impurities to a level that effectively reduces and/or eliminates the impurities and results in the reduction or elimination of the contamination of silicon metal during the milling process.